Botany Bay was the destination of the First Fleet, a group of convicts and military, who traveled to Australia in the late 18th century to establish a penal colony, but it was not established at Botany Bay due to the lack of fresh water, and the expedition moved north to found Sydney. In ENT: "The Augments" it is referred to in the present tense, therefore implying that it was at this time again a prison colony, but in TOS: "Space Seed" it is referred to in the past tense, so the colony might have been discontinued. However since Kirk suggested the ship was named after the colony, he was undoubtedly referring to the first penal colony.